code: def test_flat_peak_local_max():
      image = np.zeros((5, 5))
      image[1:3, 1:3] = 10
      peaks = peak_local_max(image, min_distance=1)
      np.testing.assert_equal(len(peaks[peaks == 1]), 4)
  
file_path: nilearn/nilearn/_utils/tests/test_ndimage.py
imports: import numpy
  import pytest
  from nilearn._utils import data_gen
  from nilearn._utils.ndimage import largest_connected_component, peak_local_max
label_desc: Use image node_id 3 for calling a global function with example usage: test_flat_peak_local_max() without return types